1. Field of the Invention
This invention relates to a disk player, and more particularly to a system of moving its pickup to the home position in the disk player.
2. Prior Art Description
In general, in optical disks such as digital audio disks and video disks, the record data start point is positioned in the inner periphery, in which table-of-contents (hereinafter referred to merely as "TOC", when applicable) data such as the number of program data recorded therein and addresses representing the positions of the program data are recorded.
In playing such a disk, first the TOC is read with the pickup, then the pickup is moved to the start position of a program data specified, and the pickup is moved along the tracks from the start position towards the outer periphery of the disk. Hence, in the disk player, in order to quickly start a disk playing operation every time, the pickup is moved near to the position of TOC of the disk (hereinafter referred to as "a home position", when applicable) at the end of each disk playing operation.
In a conventional disk player, the pickup is moved to the home position by a mechanical switch disposed near it. More specifically, the pickup is moved to the home position when a disk playing operation is suspended or accomplished as follows: The pickup is moved inwardly of the disk, and is then stopped at the position where the mechanical switch is operated by the pickup. This position is the home position.
As was described above, in the conventional disk player, the arrival of the pickup at the home position is detected by the mechanical switch disposed near the home position. Therefore, the conventional pickup control system suffers from a difficulty that the mechanical switch must be positioned with high accuracy, and the efficiency of the disk player assembling work is lowered as much. On the other hand, the home position and the record data start position of the disk may be shifted from each other when the disk is used for a long time or because of the eccentricity of the disk. Thus, it is not preferable to employ such a stationary switch to determine the home position of the pickup.